KENNEDY SPACE CENTER, FLA. - On Launch Pad 17-A, Cape Canaveral Air Force Station, workers attach the Mars Exploration Rover 2 (MER-2) , above, to the second stage of the Delta II rocket, below. MER-2 is one of NASA's twin Mars Exploration Rovers designed to study the history of water on Mars. These robotic geologists are equipped with a robotic arm, a drilling tool, three spectrometers, and four pairs of cameras that allow them to have a human-like, 3D view of the terrain. Each rover could travel as far as 100 meters in one day to act as Mars scientists' eyes and hands, exploring an environment where humans can't yet go. MER-2 is scheduled to launch no earlier than June 8 as MER-A.